As is well known, an absorbent article advantageously used as a sanitary napkin has a liquid pervious topsheet, a liquid impervious backsheet, and an absorbent core surrounded by the topsheet and the backsheet. It is important that such an absorbent article be appropriately positioned relative to the wearer's urogenital region, and should have the core absorb body fluids, discharged from the wearer, through the topsheet, and hold them without allowing their leakage to the surroundings. Generally, while the wearer is in motion, such as when walking, sitting down, or standing up, the wearer's thighs are closed, and a widthwise compressive force is exerted on the absorbent article. As a result, the absorbent article is irregularly distorted and folded with respect to its longitudinal central axis. Owing to this phenomenon, body fluids discharged cannot be appropriately absorbed and held by the core any longer. The body fluids tend to leak, particularly, to the widthwise opposite sides. Leakage to the widthwise opposite sides called lateral leakage, if any, stains the wearer's skin with the body fluids, and accordingly, the wearer's clothing, such as panties.
The term "longitudinal" as used herein refers to a direction extending on the front and back of the body along the absorbent article worn in a required state covering the wearer's urogenital region (a direction extending substantially horizontally in the back-and-forth direction of the body when the absorbent article is laid, in a flat form, substantially horizontally below the crotch region of the body standing upright). The term "widthwise" as used herein refers to a direction extending on the right and left of the body along the absorbent article worn in a required state covering the wearer's urogenital region (a direction extending substantially horizontally in the right-and-left direction of the body when the absorbent article is laid, in a flat form, substantially horizontally below the crotch region of the body standing upright).
Conventional attempts to prevent the leakage of body fluids to the widthwise opposite sides that is ascribed to the compression of the absorbent article in the width direction include, for example, constructing the absorbent core from a plurality of core pieces laid in layers in the up-and-down direction and/or arranged side by side in the width direction. Such conventional attempts are disclosed in Japanese Laid-Open Patent Publication Nos. 5-115506 and 5-84261, Japanese Laid-Open Utility Model Publication No. 5-28327, British Patent 23,103, and U.S. Pat. Nos. 3,071,138, 3,653,382, 3,954,107, 4,340,058, 4,589,876, 4,973,325 and 4,988,344.
The conventional absorbent article having the core constructed from the plurality of core pieces poses the problem that the leakage of body fluids to the widthwise opposite sides cannot be prevented fully satisfactorily, and/or the structure is considerably complicated and the cost of manufacturing is high. The present invention has been accomplished in the light of the above-mentioned facts.
It is, therefore, an object of the present invention to provide a novel and improved absorbent article which, when undergoing a widthwise compressive force, is deformed in the width direction without being distorted inappropriately, whose required site is kept at the required position of the wearer's urogenital region, and which thus prevents the widthwise bilateral leakage of body fluids fully satisfactorily.
It is another object of the present invention to provide a novel and improved absorbent article which, although being producible for a relatively low cost and with a relatively simple structure, prevents the widthwise leakage of body fluids fully satisfactorily, even when a widthwise compressive force is exerted thereon.